Mining cutter bit



Dec. 15, 1942. H. M. STEPHENS 2,305,040

MINING CUTTER BIT Filed Dec. 50, 1940 H15 ATTORN Patented Dec. 15, 1942 UNITED. STATES 'PATENT OFFICE MlNING CUTTER rr; Henry M. Stephens, Montgomery, W. Va.

Application December 30, 1940, Serial No. 372,233

2 Claims.

This invention relates to bit holders and particularly to a mining cutter bit used in connection with the mining of coal and ore or the like, or in such places as require the use of a bit of the type for cutting through a material, and has for its principal object the provision of an improved construction of this character which is highly efiicient in use and economical in manufacture.

Among the salient objects of this invention is the provision of an effective and inexpensive arrangement for releasably holding and latching the bit to its chuck.

The present invention relates to an improvement over that shown in my companion applications filed on even date hereof, one bearing Serial No. 372,234 and the other Patent No. 2,262,592 issued November 11, 1941.

Heretofore in the employment of mining cutter bits of the type hereinafter described, due to the lack of firmness in holding the bit in place, a vibratory action would be transmitted to the bit, ultimately resulting in crystallization of the shank thereof and the breakage or dislodgement of the bit from its chuck or holder. In many instances in bits of the type hereinafter set forth, by virtue of the particular and special means adapted for holding the bit in its place upon the chuck, either the chuck or the shank of the bit, in order to make room for the attachment, was greatly weakened and often weakened to the point where, when the bit was subjected to rough usage, breakage at the line of weakened union occurred.

It is therefore one of the many objects of this invention to provide a bit which is attached to the chuck holder in a manner such as will prevent these known disadvantages.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawing showing the preferred form of construction, and in which:

Fig. 1 is a side elevational View of the cutter bit assembly;

Fig. 2 is a plan sectional detail view of the same;

Fig. 3 is a fragmentary sectional detail view of the same showing the bit in partially removed position from its chuck or holder; and

Fig. 4 is a perspective view of the bit with portions broken away; and

Fig. 5 is a fragmentary plan view of the bit and holder therefor, showing a modification of construction, with part broken away in section.

To accomplish the many objects of the present invention, I provide a chuck or holder I0 having the usual eyelets I I for attachment in chain formation when a. plurality of. cutter bits are employed in a manner well known in the art of m r This chuck includes a transversely extending passage I2 adapted to slidably receive a shank I3, the passage I2 and shank I3 each being formed in cross section to correspond one to the other. The shank I3 is formed as an integral part of a head i4 having a cutter bit socket I5 of a shape which necessitates the insertion and withdrawal of the bit I6 in one direction.

The shank I3 is detachably held in place by a set screw I7, the inner end I8 of which passes into a tapered recess I9 so as to assure a firm and proper wedging relationship between the shank I3 and the inner end portion of the set screw I1. A latch structure generally indicated at 20 is provided for holding the cutter bit I6 in place. In the present instance, this latch structure comprises a dog 2| having a tapering edge 22 corresponding to the tapering edge 23 of the bit Hi. This latch dog 2| is further provided with a notched-out portion 24 through which is disposed a key 25 projected through aligned openings 26 formed in the head I 4 and adapted to slidably lock the dog 2| in the head I4. The inner end 27 of the dog 2| is preferably flush with the surrounding surface 28 of the shoulder portion 29 of the head I4. This shoulder portion 29 is adapted, when the shank I3 is properly locked in the passage I2, to abut the adjacent surface 30 of the chuck I0. When this shoulder 29 is in this abutting relation, it will be noted that the end 21 of the dog 2| is firmly locked in latching position against the cutter bit I6 so that the same cannot be accidentally displaced from latching position.

The recess I9, as shown, is tapered and has an additional function to that which is hereinbefore stated. In this connection this recess I9permits the shank I 3, when the set screw I1 is partially removed from projection in the passage I3, to be withdrawn to the position shown in Fig. 3, whereby to allow the dog 2| to be moved from latching position to allow withdrawal of the cutter bit I6. In this it will be noted that the cutter may be unlatched from its position in the head I4 without the complete withdrawal of the shank I3 from the passage I2 of the chuck I I].

It is significant to note that the construction of the means for latching the bit to the chuck is substantially simple and inexpensive and that by virtue of the relationship of the various parts a e-HM. i

when in assembled relation, neither the cutter bit nor the holder or chuck is weakened; that to remove the cutter bit it is necessary first to remove the shank l3 a substantial distance from position in the passage l2 to permit the expeditious movement of the dog from latched position against the bit substantially in the manner shown in Fig. 3.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of passage therethrough, a shank slidably mounted in the passage and provided with a tapering recess in one edge thereof, a set screw adapted to be threaded into said recess, said set screw permit-ting partial withdrawal of the shank from the passage when partially withdrawn from engagement in said tapering recess, said'tapering recess assuring a wedging relationship between the shank and set screw, a head on said shank having a cutter bit recess, a cutter bit mounted in said recess, and latch means carried by said head and serving to latch the cutter bit in said cutter bit recess, sai-d latch means being incapable of movement from said latched position with respect to the cutter bit when the shank is disposed completely in said passage, said latchmeans including a latch member having a notched portion formed therein, and a pin member carried by said head and projected transversely of the notched portion to limit movement of the latch means from latched position with respect to the cutter bit.

2. In combination, a tool receiving head, a tool slidably mounted in said head and having a tapering edge, a dog slidably carried by the head and having a tapering edge adapted to engage the tapering edge of said tool for latching said tool in said head, said head having a shoulder adapted to engage an adjacent object, and said dog being held in said latched position by said object, substantially as described, said dog having a notched portion and a pin member carried by the head and projected through the notched portion and serving to limit the movement of said dog from latched position with respect to said tool.

HENRY M. STEPHENS. 

